It'a actually a one-trick pony...or not to be so harsh...a two or three-trick pony;-).
This VSTi is definetly no all-rounder but if you're after really "in the face" basslines and leads like one could create with Access Virus or similar synths, you should give this one a try.
The UI is a bit old school and could be improved regarding usability (missing auto-center, some knobs too sensitive) and I'm missing stuff like portamento (glide), but all in all it's a good value for money.
The current version seems to suffer from stability issues when run in Reaper, maybe there will be an update fixing this some day.
The GUI is quite nice and functional, just the readability could be better if the background wouldn't be such a dark colour though.
The sound is really good. To my ears BS-1 sounded best from all SF2-players I came across so far. Just the volume is a bit low sometimes with certain soundfonts.
For the features, it's all there that one may need to tweak when using soundfonts. However, I never got program change via MIDI working here and by the lack of a documentation and any customer support (see further down) I have to substract some points here.
Documentation... what documentation?! There ARE NO docs at all! I couldn't believe it, but it's true: Also after I payed for BS-1 I did not get any, nor a link to it. The only "docs" you will find are the short infos on the home page, that's all...
Sorry to say, but the support is just worse. All contact options you have is an email-address and I tried to contact the developer for three time but didn't ever get any response.
BS-1 is stable as long as you don't touch certain settings while the sound is running.
Conclusion: If you're in need of a cheap and good sounding SF2-player, go ahead but be aware that you won't get any help if you run into trouble with it. If you have some extra money, better go for VSampler or any other soft-sampler that loads soundfonts.
I bought Slayer2 right when it came out. I had played aroung with Slayer1 before, so I was a bit disappointed by Slayer2 as it missed the "bite" of Slayer1. This has been fixed with the 2.5 release of Slayer2 meanwhile.
The GUI is really great, if the readability of some controls would be improved, it would be perfect IMO.
The sound is simply outstanding! There is no other other electric guitar simulation that I'm aware of that comes any close to this quality. Brilliant!
Regarding the abilities to change the sound character, there's nearly every feature I can imagine. The only weak point here is the "humanize" feature, because it doesn't offer as much playing alternation as I would expect from such a function.
The documentation is quite good. All features are explained widely here. I only miss some playing hints here since it's not very easy to "think" like a guitar player if you can't play guitar (like me). Some tutorial would be appreciated very much.
The presets could be tweaked a bit better. They are all quite usable, would I always have to tweak some settings before they fit into my mixes. Also, some of them sound a bit too identical IMO.
The customer support is simply great! I had some trouble with Sonar's VST wrapper when I got Slayer2. After some email exchange with the devs they gave me a bugfixed beta-build that solved my issue.
For the VFM: Just compare it yourself! Download the demos from reFX and test them. Then compare the price/features ratio with what you get for this money from other companies. Slayer2 is definitively worth one's salt.
Slayer2 is solid as a rock. I wasn't able to crash it here, even if I overloaded my system with plugins while running low latency.